The Digital Body Development System (DBDS) was launched in 2003. The project has the potential to save U.S. automobile manufacturers $3.5 billion in vehicle launch costs by shortening lead times, reducing the number of physical evaluation model builds, and improving the quality of vehicle body assemblies. The four-year project will involve significant new development of engineering software systems and will culminate in a validation phase implemented at two vehicle launches—one at Ford Motor Company and one at General Motors Corporation.
The project is a joint venture between Altarum Institute and the Center for Automotive Research (CAR). The joint venture includes an inter-disciplinary team consisting of auto companies (General Motors, Ford), software providers (EDS/UGS-PLM), die tooling, foundries, assembly tooling, metrology equipment providers, and other research organizations (Wayne State University and University of Michigan).
DBDS will enable the implementation of a virtual functional build methodology to help designers and vehicle launch teams make better decisions faster and understand the quality, cost, and timing impacts of those decisions. Modules under development identify problems in the current design of a vehicle body, suggest potential changes, and evaluate these changes with respect to their impact on manufacturability and expected cost.
DBDS takes a specific design of a car body or sub-assembly in the launch phase of a new vehicle, analyzes it for deviations from its functional specification, and seeks to determine changes to the design that reduce or remove these deviations (FIG. 1). The design provided to the DBDS is called “base design,” and includes information about individual parts, their assembly process, and tools and fixtures used during the assembly. Once the launch team implements some or all of the suggested changes, DBDS receives the new base design and repeats the analysis and improvement process until the functional specification is met.
DBDS analyzes a given design by simulating the specified assembly process, using an existing assembly simulation (currently Vis-VSA by UGS/PLM). Deviation from the functional specification is measured on the virtual end product of the simulated assembly.
If the base design deviates from the functional specification, DBDS will begin generating alternative solution candidates, which are sets of changes to the base design that may be suggested to the launch team. DBDS applies the design changes represented by a new solution candidate to the base design, creating a new design. This new design is again analyzed for its deviation from the functional specification, using the assembly simulation. If the new design is a sufficient improvement compared to the base design, then DBDS will propose the solution candidate (set of changes) to the launch team. Otherwise, it will continue generating and evaluating new solution candidates (FIG. 2).
Algorithmically, the repeated generation and evaluation of new solution candidates utilizes a heuristic search process through the high-dimensional space of possible design changes, guided by a utility function that is based on the degree to which the new design reduces deviations from the functional specification compared to the base design.